jsp 下载文件 AJAX不支持返回流类型 采用jquery easyui的表单提交

//JS

filedownLoad:function(id){

downForm = $("#fileForm").form(); downForm.form('submit', { url : ctx+'/file/downLoad.shtml?fileid='+id, type : 'POST', success : function(data) { if(!data.flag){ layer.msg("资源不存在!"); } } })

}

//JSP页面

 <div class="file-name">                                         ${item.file_name}                                          <br>                                         <form id="fileForm" method="post">                 <input type="hidden" id="fileid" name="file_id" value="${item.file_id}"/>                 </form>                                           <small>上传时间：<fmt:formatDate value="${item.upload_time}" pattern="yyyy-MM-dd"/><a href="javascript:void(0)"  οnclick="fileview.filedownLoad(${item.file_id});"  style="margin-left: 40px;font-size:14px; color: #676a6c;" ><i class="glyphicon glyphicon-cloud-download"></i> </a></small>                                     </div>

//控制层

@RequestMapping(value = "/downLoad") public void downLoad( HttpServletResponse response,Integer fileid,PrintWriter writer) throws Exception { JSONObject result = new JSONObject(); Map<String, Object> map = new HashMap<String, Object>(); map.put("file_id", fileid); List<SpFile> filelist = spFileService.selectSpfileByObjectid(map); String hostpath = SysConfigManager.getInstance().getText("/config/system/file"); String path = hostpath+filelist.get(0).getPath();         File f = new File(path);         if (!f.exists()) {         result.put("flag", false);         response.setContentType("text/html;charset=utf-8");     writer.println(result);         }else{         FileUtils.down(response, path,f.getName());         }     }

//下载文件的方法

public static void down(HttpServletResponse response, String path, String filename) throws Exception { File downloadFile = new File(path); InputStream in = null; OutputStream out = null; try { response.reset();  response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(filename, "utf-8")); in = new FileInputStream(downloadFile); out = response.getOutputStream(); byte[] bytes = new byte[1024]; int length; while ((length = in.read(bytes, 0, bytes.length)) > -1) { out.write(bytes, 0, length); } } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { in.close(); out.flush(); out.close(); } }